Burner assembly for gaseous fuel



June 2, 1964 J. 5. ZINK ETAL 3,135,315

BURNER ASSEMBLY FOR GASEOUS FUEL Filed Oct. 16. 1961 INVENTORS JOHN SMITH Zl/VK HE RSHE L GOOD/V/GHT ROBERT D. REED ATTORNEY 3,135.315 BURNER ASSEMBLY FOR GASEOUS FUEL John. Smith Zink, Hershel Goodnight, and Robert D.

Reed, all of Tulsa, Okla, assimiors to John Zink Company, Tulsa, Okla a corporation of Delaware Filed Oct. 16, 1961, Ser. No. 145,127 3 Claims. (Cl. 158--99) The present invention relates to a burner assembly for gaseous fuels and more specifically pertains to a burner head in association with a ceramic member with the assembly so constructed as to provide an elongated thin flame and with the parts so arranged to avoid overheating the burner head by the heat developed from the burning fuel.

Burner heads are known for the production of elongated thin flame but when such a burner head is employed with a ceramic member there has been rapid destruction of the burner head as a consequence of the heat developed by the burning fuel. One factor involved in prior burner assemblies of this type causing United States Patent overheating of the burner head has resulted from low pressure conditions developed along the sides of the burner head which causes the hot gases from the combustion zone to be drawn over the burner head. Heat is reflected by the ceramic member onto the burner head and the flame developed closely adjacent the downstream face further heats the burner head contributing to rapid destruction of the metal.

It is an object of the present invention to provide a burner head for gaseous fuel for the production of,

elongated thin flame and with the side surfaces thereof and the downstream end of the burner head so shaped I and constructed as to cause the cool secondary air to sweep over the entire side surfaces of the burner head to avoid the development of low pressure zones along the sides of the burner head with the result that such portions of the burner head are cooled by the secondary air and low pressure zones are avoided to thereby prevent the hot gases from the combustion chamber from being drawn into'the presence of the burner head.

Another object of the invention is to' provide an elongated burner head with discharge ports which are so arranged that the gaseous fuel mixture escaping therethrough cools a lengthwise area of the downstream portion of the burner head and the discharge ports are so disposed that initiation' of the flame is spaced downstream from theburner head to eliminate contact of the flame with the burner head.

A further object of the invention is to provide means at the downstream end of the burner head which serves to shield side portions of the burner head from heat radiating from'the ceramic member.

A still further object of the invention is to so arrange the discharge ports in an elongated burner head for gaseous fuel so that the gaseous fuel mixture escaping through the discharge ports at relatively high velocity will develop a low pressure area in the proximity of the exit ends of the discharge ports into which the secondary air is drawn for cooling the associated portions of the burner head.

Other and further objects and features of the invention will be appreciated and become apparent as the present disclosure proceeds and upon consideration of the following detailed description taken in conjunction with the accompanying drawing wherein an embodi ment of the invention is disclosed.

In the drawing: i FIG. 1 is a sectional view of the burner assembly illustrated in association with the wall of a chamber in which heat is to be developed.

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FIG. 2 is a side elevational view on a smaller scale and taken on the line 22 of FIG. 1.

FIG. 3 is a plan view of the burner head.

FIG. 4 is an enlarged fragmentary sectional view of the downstream end portion of the burner head and portions of the ceramic member.

FIG. 5 is an end elevational view on a smaller scale showing the relationship of the width of the burner the burner head 16 is slightly greater than the width thereof so that spaces are provided between the sides of the burner head and the confronting inner faces 17 and 18 of the refractory member 10. The faces 19 and 21 of the ceramictile diverge from each other in proceeding downstream from the respective faces 17 and 18 at angles of about fifteen degrees.

The burner head'16 is of elongated construction as shown in FIGS. 2 and 3 and includes a downstream end plate 22 and side walls 23 and 24. An upstream wall 26 and end walls 27 and 28 provide a closed hollow chamber within the burner head. A conduit connection 29 is provided for supplying gaseous fuel under pressure. into the chamber within the burner head. The

outer face of the wall 1 2 and the outer face of the ceramic member are desirably covered with sheet metal 31. The burner head may be supported in position within, the ceramic member 10 by means of a bracket structure 32 which may form .a part of an air register for admitting controlled quantities of secondary air through an opening 33.

A structural characteristic of the burner head which ingly not parallel and converge towards each other in proceeding downstream of the burner head.

In the embodiment illustrated the downstream dimension of the burner head as indicated at L is about three and one-quarter times the Width W. This ratio is the minimum to provide the inwardly converging side walls 23 and 24 and requires the least material in forming the burner head. The length L to width W ratio may exceed three and one-fourth to one without losing the beneficial result of having the secondary air flow along major portions of the downstream dimensions of the side walls 23 and 24. The air flowing along the side walls 23 and 24 is partially deflected by the side edges of the plate 22 as shown in FIG. 4 because all of the secondary air does not return to move along the outer faces of the side walls 23 and 24 enroute to the plate 22.

Another characteristic feature of the burner assembly pertains to the location and disposition of the discharge ports for the escape of the gaseous fuel mixture from the chamber within the burner head. The discharge ports are arranged in spaced relationship along the length of the elongated burner head 16 and one aligned v a a row of discharge ports 38 have their axes converging towards a central plane of the burner head at an angle of approximately thirty degrees. The other aligned row of discharge ports 41 are spaced along the length of the burner head and the axes of the discharge ports forming this row converge towards the central plane at approximately thirty degrees. The gaseous fuel is supplied through the conduit connection 29 under substantial pressure and the gaseous fuel escaping through the discharge ports 38 and 41 is at high velocity. An extremely low pressure zone is developed in an elongated area immediately downstream of the discharge ports 38 and 41.

This low pressure zone draws the secondary air after it has been deflected by the side edges of the plate 22 into the low pressure zone adjacent the discharge ports 38 and 41 as indicated by the arrows in FIG. 4. The movement of the air along the downstream face of the plate 22 enters into the presence of the gaseous fuel mixture escaping through the discharge ports to such an extent that the flame begins at approximately at the point of impingement of the gas jets flowing from the two rows of discharge ports and at a point which is spaced downstream from the downstream face of the plate 22. Accordingly the flame does not contact the plate 22 and avoids undue heating of this portion of the burner head. The air flowing in the direction of the arrows in FIG. 4 sweeps over the downstream surface of the plate 22. The downstream face of the plate 22 is thus, scrubbed with the secondary air and the plate 22 in the areas extending laterally beyond the side walls 23 and 24 is also scrubbed by the cooling secondary air. The gaseous fuel flowing through the discharge ports 38 and 41 assists in cooling the burner head. 7

The inward converging faces of the side walls 23 and 24 promotes the return of the cooling secondary air to scrub the sides of the burner head. The abrupt increase in the width of the burner head as provided by the plate 22 serves the function of promoting movement of the cooling secondary air over the downstream portion of the burner head to reduce the temperature and thus reduce deterioration of the burner head as a consequence of the heat developed by the combustion of the fuel. The portions of the plate 22 which project laterally beyond the side walls 23 and 24 at the downstream ends thereof shield the sides of the burner head from the radiant heat emanating from the ceramic member 10.

While the invention has been described with reference to specific structural features and one type of ceramic member and with regard to the structure of the burner head it will be appreciated that changes may be made in all of the elements including changes in the discharge port arrangement together with changes in the ratio of the height of the burner head with respect to the width. Such alterations and others may be made together with changes in the overall assembly without departing from the spirit and scope of the invention as set forth in the appended claims. a

What we claim and desire to secure by Letters Patent is:

1. A burner assembly for gaseous fuel comprising, a ceramic member having an elongated opening therethrough provided with confronting faces, an elongated burner head within said opening, side walls on said burner head having outer surfaces spaced respectively from said faces, end Walls and a plate closing the area between. said side walls providing a chamber within the burner head, means for supplying gaseous fuel under pressure into said chamber, means guiding air for movement downstream of the assembly between the vicinity of exit ends of said discharge ports drawing air over side edges of the plate and along the downstream surface of said plate.

2. A burner assembly for gaseous fuel comprising, a ceramic member having an elongated opening therethrough provided with confronting faces, an elongated burnerhead within said opening, side walls on said burner head having outer surfaces spaced respectively from said faces, end walls and a plate closing the area between said side walls providing a chamber within the vburner head, means for supplying gaseous fuel under pressure into said chamber, means guiding air for movement downstream of the assembly between the side walls and said faces, said plate having a row of discharge ports therein with their axes converging towards a central plane of the burner head, said plate having another row of discharge ports with their axes converging towards said plane whereby the gaseous fuel intermingles downstream of said plate providing a low pressure condition in the vicinity of exit ends of said discharge ports drawing air over side edges of the plate and along the downstream surface of said plate, said outer surfaces of said side walls converging in proceeding downstream of said burner head, and said plate having its side edge portions laterally beyond the planes of the outer surfaces of said side walls at the downstream ends thereof.

3. A burner assembly for gaseous fuel according to claim 2 wherein the dimension between the outer surfaces of said side walls at the upstream end of the burner head is one and one-tenth times the width of said plate, and the length of the burner head measured along the axis thereof being approximately three and one-quarter times the width of said plate.

References Cited in the 'file of this patent UNITED STATES PATENTS 

1. A BURNER ASSEMBLY FOR GASEOUS FUEL COMPRISING, A CERAMIC MEMBER HAVING AN ELONGATED OPENING THERETHROUGH PROVIDED WITH CONFRONTING FACES, AN ELONGATED BURNER HEAD WITHIN SAID OPENING, SIDE WALLS ON SAID BURNER HEAD HAVING OUTER SURFACES SPACED RESPECTIVELY FROM SAID FACES, END WALLS AND A PLATE CLOSING THE AREA BETWEEN SAID SIDE WALLS PROVIDING A CHAMBER WITHIN THE BURNER HEAD, MEANS FOR SUPPLYING GASEOUS FUEL UNDER PRESSURE INTO SAID CHAMBER, MEANS GUIDING AIR FOR MOVEMENT DOWNSTREAM OF THE ASSEMBLY BETWEEN THE SIDE WALLS AND SAID FACES, SAID OUTER SURFACES OF THE SIDE WALLS CONVERGING TOWARDS EACH OTHER IN PROCEEDING DOWNSTREAM OF SAID BURNER HEAD PROMOTING THE FLOW OF AIR ALONG MAJOR PORTIONS OF SAID OUTER SURFACES, SAID PLATE HAVING ITS SIDE EDGE PORTIONS EXTENDING LATERALLY BEYOND THE OUTER SURFACES OF SAID SIDE WALLS, AND SAID PLATE HAVING DISCHARGE PORTS THEREIN WITH THEIR AXES CONVERGING WHEREBY THE GASEOUS FUEL INTERMINGLES DOWNSTREAM OF SAID PLATE PROVIDING A LOW PRESSURE ZONE IN THE VICINITY OF EXIT ENDS OF SAID DISCHARGE PORTS DRAWING AIR OVER SIDE EDGES OF THE PLATE AND ALONG THE DOWNSTREAM SURFACE OF SAID PLATE. 